grok-4.3 vs gpt-5.5-2026-04-23

Pricing, Performance & Features Comparison

grok-4.3

Authorxai

Context Length1M

Reasoning

Providers1

ReleasedApr 2026

Knowledge Cutoff–

License–

xAI’s value flagship with a 1M-token context window and unified reasoning effort control; the retirement redirect target for the grok-3 and grok-4 generations.

Input$1.3

Output$2.5

Latency (p50)5.9s

Output Limit–

Function Calling

JSON Mode

InputText, Image

OutputText

xai

in$1.3out$2.5cache$0.2–

Latency (24h)

Success Rate (24h)

gpt-5.5-2026-04-23

Authoropenai

Context Length1M

Reasoning

Providers1

ReleasedApr 2026

Knowledge CutoffDec 2025

License–

OpenAI’s April 2026 frontier model and the recommended migration target for the o-series and GPT-5 generation.

Input$5

Output$30

Latency (p50)4.7s

Output Limit128K

Function Calling

JSON Mode

InputText, Image

OutputText

openai

in$5out$30cache$0.5–